More Elegant Settable Methods?

[jwatson-CO-edu via Digitalmars-d-learn]

Hi,

I am trying to create a struct with a settable method that has 
access to the struct scope.
Is this the only way?
Is there a way to give access without explicitly passing `this`?
```d
import std.stdio;

struct TestStruct{
    float /*------------------*/ a;
    float /*------------------*/ b;
    float function( TestStruct ) op;

    float run(){
        return op( this );
    }
}

void main(){
    TestStruct ts = TestStruct(
        2,
        3,
        function( TestStruct s ){ return s.a + s.b; }
    );

    writeln( ts.run() );
}
```